Train-control apparatus



Dec. 18, 1928.

P. ACLAW-ORD TRAIN CONTROL APPARATUS 4 Sheets-Sheet 1 wd y V Q JWM M D H/Jub J M m original E iuled Jan- 24, 1925 P. J. CLIFFORD' TRAIN CONTROL APPARATUS Dec. 18, 1928.

Original Filed Jan. 24, 1925 `4 Sheets-Sheeit- 7c* xm. .1 A

D 1s, 192s.

1,695,880 P.,J. cuFFoRD l TRAIN CONTROL APBARATUS Original Filed Jan- 24. 1925 4 Sheets-Sheet 5 gjm/ventola uw 1s, 192s. 1,695,880

` P. J. CLIFFORD TRAIN coNTRoL APrARATus Original Filed Jan. 24, 1925 4 sheets-sheet 4 d .fm-@H .lf4 /f I Mil" S11/manto@ Paf d Jai/74rd M album rasata nee. is, 1928.

' nitro staresY PArENT' oFFicE.

rATRrcK J. oLirroRD, or FALLS, rninvsYmr'ANIA,v AssiGNoR To TRAIN CONTROL coRroRATron or AMRRroA, 0F NEW YORK, N. Y., A ooRroRATioN or DELAWARE.

TRAIN-CONTROL APrARATUs.

Application filed January 24, 1925, Serial No. 4,484. Renewed May 15, 1928.

rlhis specilication is a continuation in part ot' that belonging to application. for Letters Patent of the United States tiled by me Aug. Q1, 1918, ,Th-.250,803 and it also embodies subject matter disclosed in my application-for LettersPatent ot thek United States filed by me Mar. 2li, 1919, Serial 'Niii'nber28t,731.

1n the accompanying drawings:

Figure 1 is a diagrammatic view of the system;

Figure 2 is a detail view oi' the valve for eliminating the 'functions ot the automatic train stopping system.

Figure 3 is a detail view of the supplemental valve combinedwith the engineers valve,

portion ot the latter being shown.

Figure l is a .detail view of the trigger valve.

Figure 5 is a detail view of the automatic' air release valve.

Figure 6 isa detail view of the engineers disabling valve.

Figs. 7, 8, 9, 10 and 11 are views relating to details ot the trigger valve.

Fig. 12 is a detailed view oi' a modified structure relating to the trigger valve.

Fig. 13 is a detailed sectional view of the contact valve.

lllien the roller 1 on the engine strikes the ramp or track implement the contact valve is littedalloiving air pressure from the ordinary equalizing reservoir of the Westinghouse system to pass from pipe 8 to pipe 141 and thence to cylinder a, Where acting on a 'piston b a valve 19 is turned through rod 17 and arm 18,

fthe turning ot' the valve connecting by its passage or part 9,2 the pipe 13 with pipe 15, so that pressure from the Westinghouse equalizing reservoir can pass to a casing A., causing valve therein to open port 44 tor the release o1E air from the train pipe, thereby setting the brakes. The air pressure` let into the casing A. also passes through pipe 51 to an engineers disabling valve in casing B and sets this to cut'o' communication between pipes and 50, thus preventing the engineerfrom recharging the train line pipe, by operating the Westinghouse automatic brake valve H6, until after a prescribed period of time has elapsed during which time the train will have come to a stop. This prescribed period rci" time which must ela-psc vbetore the engineer can recharge the train line pipe and take off the brakes is due to the tact that the air pressure introduced into the casings .at A and B e'liect will not be initiated until pressure has built up in ipe 15 suticientlv that assin@ .L p Y u 9 7 ca ,through bleed`port 1521 and bleed pipe 37 ,V the valve 19 'Will be turned asv hereinafter described to cut` off lcommunication between pipes 13 and 15 and open bleed port 22 allowing air pressure kto bleed from valve casings A and B, and only When this has occurred can the'disabling valve Z9, be reset by the'engineer sending pressure through the pipe 57 from the ordinary Westinghouse independent brake valve S6.

As stated above the air pressure for operating the automatic air release valve A and the engine'ers disabling valveB is derived from the equalizing air reservoir of the West inghouse system. y

Thedisabling valve is located in the pipe connection 50a, 50 extending from the main reservoir to the engineers valve organization that when this pipe connection is closed, by the disabling valve B, theengineer will not. be able to supply'air to the train pipe for recharging the same.

Now describing the parts, and operations f ,through the port 7 and pipev 8, being thus in constant open communication With'the compressed air supply in said reservoir.

The plunger or stem 2 is provided With a head or valve member 9 provided With suit-` able packing and resting .on the seat 10, and

below the head the stem has a circumferential groove 11 and inone side of thel stem there is formed a passagef12 communicating with' the said annular groove and also With a discharge port or passage 2O extending through the 5 and having a pipe 14 extending therefrom toa .cylinder a containa piston Z9 connected by a rod 17 With the 18 of rotary trigger valve member 19, which controls the inlet or delivery of air, pressure from the equalizing reservoir through the pipesy 13 and 15 to the automatic reiease valve A, which controlsthe automatic setting of the brakes, this valve 19 having the port or passage 22, which, When the valve is turned into a certain angular posi-- instrument or ramp air iroi'n the equalizing reservoir will pass through the pipe 8,-passage 7, chamber 1l, annular groove'11, due to the lifting of the head or valve member 9 from its seat, and the air will thence pass through the port 12, passage 20, and pipe 14C to the cylinder a., where acting upon the pistoii b the rod 17 through arm 18 Will turn the valve 19 and thus pipes 13 and 15 will be throvvn into communication and the air from the equalizing reservoir Will pass through these pipes to the automatic release valve A to set the brakes and to the engineers disablingvalve shown generally at B.

The valve arm 18, when the valve is operated, as just described, is set in anangular position o'l about thirty degrees.v This valve also has an arin 13 Which, when the valve is turned as just described, presents an opening to be engaged by a locking bolt 26 spring pressed and iounted in the casing, said bolt serving to hold the valve in operated position long` enough` to insure the proper operation of the brakes. y

For unlocking the valve and restoring it to normal positionthe following arrangement is provided:

The bolt- 26 is acted on by an incline 27 of a cam slide 28 consisting of a bar attached atoiie end to a piston 36 in a chamber 35, Which chamber at a point back of the piston is connected with the air pipe 15 by a .small port 15a. The other end of the cani slide is acted on by a spring 30 in a casing 31, Which springzis adjusted as to its tension by a screw 32 bearing on a washer 33, a second Washer 3-1 being arranged between the spring and the cani slide. i passage or pipe 37 connects the interior of the chamber 35 with the pist ton chamber a.

fter the piston of the automatic air yrelease valve il and the piston iii the engineers disabling valve B are operated by the pressure supplied thereto through the pipe 15 the pressure Will build up in the said pipe 15 and this pressure will nonY pass into the chainber 35, through small. port 15, previous to the operation of the pistons just mentioned, and While the flow oin air through the pipe 15 is continuing and moving` the said pistons oie. A. and B the piston 36 `will remain in the position shown at the right of the chamber 35,

" due to the spring 30, the strength oit which is so adjusted that While any air is passing through pipe 15 the spring Will hold the piston 36 in the position shown, but as soon as the pistons in the valve chambers of the automatic air release valve A and the engineers. disabling valve B have been operated and the pressure builds up in pipe 15 it Will pass through port 15a and build up also inchainber 33 forcing the .piston 3G to the lefty and thus operating the cani slide to retract the bolt 26 against the pressure ot its spring and thus releasing the arm 18 oi the rotary valve, so that this valve may be returned to normal position, and thus cut oliil the air from the pipe 15. rilhis operation of the valve baclr to normal position takes place by thev built up pressure oit air passing from cylinder 35 .through the pipe 3? into tie chainl er a,

Where acting on the piston o it will move said piston leftivard, and through the rod 17 the arm 18 of the valve will be moved leftward, thus returning the valve to normal position. Y

rlhe return of the valve 19 to normal Vposition, as just stated, cuts oft the .supply of air to pipe 15 and at the saine timeV brings a passage 22 inthe valve to register with the port 24x of passage 2li and the port 22 for bleeding the pipe 15 and the piston chamber et the automatic air release valve i and the engineers disabling valve at B. The port of the passage 23 is shown at 23X.

The ports 23X, 211x extend vertically in a valve .seat block 19x on top of which the valve 19 rotates, the port or passage 22 in the valve 19 having vertical portions 22c to register with the ports 23X, 24X. lThe bleeding port 22 extends vertically through seat block 19X.

Reverting to the contact plunger 2 it will be observed that this is guided by a rpin 2 passing through a slot 2X, Which holds the plunger troni turning, and keeps the passage 12 in registration with the port 20. This pin and slot connection also limits the upiva-rd movement ot the plunger and the roller 1 is kept in proper position to vroll prop-v erly on the tracl; instrument.

Revcrting to the trigger valve 19 a port 19(y extends through the casing of this valve troni the air pipe 13 to the chamber in Which the valve 19 is contained, so as to exert air pressure Vdownwardly on said valve'to equalize the airpressure tending to litt said valve, enabling the valve to be easily operated.

The valve block 19 is provided 1with two ribs 19"-l on its upperside between which engages a lug` or rib 13a of a key or plu vvhich has a square portion at 18 to receive the lever 18, and a threaded portion to receive the nut 18h. he chamber containing Athe valve is closed by a cover 19".

rllie air .pressure in the chamber containthe valve 19 ei-Iuts an upward pressure. against the plug and leeps'it air tight the Washer on the bottom of cover 19.

'The' automatic air release valve comprises casing l10 in which. a valve member 11 slides, said valve having ports ll2, L13 ot graduated sizel and a long port 44-by Which the air from the. train line pipe may be released to atmosphere throughther port 44 of the casing, when the valve is :moved to the right,

thereby bringing the ports, in the order oi' their size, 'to the port 450i the train line Vpipe for the gradual setting of the brakes. The vaive is moved by pressure let into the pipe by the trigger valve 19, Which pressure acts upon a piston 46 in the cylinder 47, the stem 48 of this piston carrying the automatic air release valvemember. 41 along With it.

The automatic air release valvewvill be returned to normal or closed position bythe spring 48 When the air pressure is reduced in pipe 15 by bleeding out through the port 22 at the trigger valve 19, as above described. y

rllhe engineers disabling valve B consists of a piston slidable in a casingvand having a port or circumferential groove 49 adapted to connect the pipes 50, 50a forthe passagey ot air to the engineers-valve for recharging the train line pipe, but when the piston .is moved ifroin the position shown communication between the'pipes 50, and 50a will be cut oli'. A pipe 51 leads tothe casing at the y lett oi' the said piston valve, this pipe extending from a port 52 inthe casing of the automatic air release valve. This portis controlled by a valve 53 sliding with the automatic air release valve being connected With the stenrof the piston 46. This valve 53 also controls the inletof air through the port -j 54 iroin the pipe 15 by yWay of the cylinder 47 and by-pass 55and it also controls a bleed port 56, by which pressure is removed from the left side of the disabling valve at B to allow said valveI to returnlleitvvard at such time, after said pressure reduction, that the engineer may operate the independent brake valve S?, and send air through pipe 57.V The valve 53 has ports 53u and 53b and it is shown in position to allow the escape or bleeding oi the pressure through the port 53a, 53b and 56. Y Y .f

T ie engineers independent brake valve S has a pipe 57 connected with its exhaust poi't and this pipe connects with the casing of the disabling valveB attlie right oi the piston thereoi. The casing` of this valve has an exhaust port l/V therein, through which the air from the exhaust of the valve S6 passes out.

1t will be understood thatv Whenthe system is operated by the roller 1 striking the ramp resulting in the release of train pipe pressure through port 44 of valve at A and the setting of the e-ngineers disabling valve at B in disabling position the engineer canrecharge the train line through pipes 50, 50a to release the brkes until after the prescribed period of time has elapsed necessary to reset the trigprl valve 19 to bleeding position and reduce the pressure on the automatic air release valve land ythevdisablingvalve, and only after these actions have taken place can the engineer recharge the train line by operating the engineersr independentbrakevalve 3G, Which will move the valve B to connect pipes 5.0, 50s,. leading from the mainy air reservoir to valve H, or from the automatic brake valve H6 of' the Vestinghouse system, to the train pipe.

In the operation ofthe apparatus when the trigger valve 19 is operated air Will be delivered from the equalizing reservoir through pipe 15 to the piston 46 of' automatic air .release valve at A thereby setting said valve 41 against the resistance of its spring in position to discharge the air from the train pipe through port 44( and thus automatically set the brakes. The movement ofthe piston 46 of this valve at A will alsoset the valve member 53 in position to deliver air pressure to the engineers disabling valve atv B,

this delivery taking place through the -bypass 55, port 54, the valve port 53", the. port 52 and pipe 51, and as a result the piston b.

Will be forced to the'leit, thus breaking communication between the pipes 50, 50, and thus disabling the engineers valve HG, (Westinghouse autom-atie brake valve), and all other parts of the system because the operation ofthe engineers independent brake valve 'Se (Vestinghouse) to admit engine-brakecylinder pressure through the pipe 57 vcannot return the piston to the left until the equalizing reservoir pressure is bled out from the right-hand side of the said piston and this reduction of pressure Will not occur until' after certain actions have transpired'antb therefor-e vthe engineers valve and systemV Will be cut out or disabled for a. prescribed period ottime during which the brakes remain set and this time is calculated to'be long enough to bring the train to a stop.y TheI actions which transpire during this prescribed period a're: the building up of pressure in the pipe 15 beyond the trigger, valve rafter the automatic air release valve 41 andV the control valve 53 reach'their positions at the right, and after the-piston valve bf reaches its left-hand position', which built'- up pi'essureresults in the unlocking and resetting of the trigger valve to normal position, after which the bleeding of the pipe 15 takes place, through port 22 allowingy the automatic air release valve-and the-*valve 53 iso .brake valve S6 and sending air through'pipe This predetermined period-ottime during lie Y fao which the system is disabled may be varied by adjusting the tension otl the resistance spring 30, by means of the screw 32, the adjustment ot this screw requiring that the 'pressure in pipe 15 be built up to a greater the disabling valve at B.

Eliminating calce.

The above mentioned system provides for bringing the train to a full stop and presupposes that the engineer is out of service through accident, sickness, or death on reaching the caution signal, or is not paying proper attention to his duty. l

These' instances are,.however, rare as compared with the number o'll eiiicient engineers in service and the` further iniproveiiintY now to be described presupposes that the engineer will be in condition to do his duty and it therefore provides means whereby ythe engineer on approaching a caution signal may continue running his train, provided he is paying attention to his work'and slows down the speed ot the train upon running into the danger Zone.

In carrying out the invention there is provided an automatic stop-eliminating-valve indicated generally at B', this being located in the pipe 15 which extends from the automatici trigger valve 19 to the automatic air release valve A of the system above described. This automatic stop eliminating valve maybe oit a piston form similar in general aspects to the engineers disabling valve B, in that the piston valve operates in a cylinder. Air is supplied to this eliminating valve from the automatic brake valve H by a vpipe 52 which extends from a supplemental valve casing i., mounted on the casing ot the automatic brake valve and having a supplemental valve h2, therein to control the inlet of air from this automatic brake valve to the pipe 52. This supplemental valve is held on it-s seat to prevent air passing through the pipe 52 to the eliminating valve by main reservoir pressure. As an illustration, l may employ a cani member 7L? on the handle of the automatic brake valve which rides over the ball 71.4 on the tluted stem ot the supplemental valve 7a2 to to 1ce it from its seat, so that-when the handle h of the automatic brake valve is turned into a position to slow down the train, the ball h4 will be depressed by the tail of the handle working over it and the valve will be opened to allow the air pressure to pass from the space k6 o't the engineers automatic brake valve, which air pressurewill pass by way oit pipe 52 to the eliminating valve operating the piston thereof, so as to cut oit 'communicationvbetween the pipe and thel automatic air release valve A andV engineers disabling valve B to thereby prevent the operation of these valves and consequently preventing stopping ot' the train.

Should, however, the engineer tail to put theautomatic br'alre valve HG in service position, i. e. for slowing down the train, the eliminating valve B will remain in its normal position, allowing communication between the pipe 15 and the automatic air release valve A and engineers disabling valve B, so that upon the trigger valve 19 operating, as a consequence ot the. contact member 1 riding over the ramp, air from the equalizing reservoir will pass through kthe trigger valve, pipe 15 to automatic air release valve A, which will operate to openV releaseport 44 allowing the escape ot air pressure from the train line pipe, and at the same time equalizing reservoir air will passthrough the lvalve.,

casing of the valve A and pipe 51 to the engineers disabling valve B, setting this in position to cut oil main reservoir air to the engineer-s valve so that the engineer cannot restore pressure to the system until a prescribed period has elapsed, this disabling action cutting oil communication between the pipes 50, a, which communication is necessary in order to recharge the train line pipe and talre oil the brakes.

The supplemental valve h2 is pressed normally onto its seat by a spring L7. The eliminat-in g valve is pressed to its normal position to allow air to pass from pipe 15 to the automatic air release valve and engineers disabling valve by a spring B. This eliminating valve is of piston form and has a. passage BX for the iiow of the air through it when in normal position.

rlhe eliminatingaction, i. e. cutting out the automatic operation of the automatic stop system can take place only when the engineer places the automatic brake valve H6 in service position.

lt, aip ter having placed this valve in service position to slow down the speed, the engineer,

by reason of becoming suddenly incapacitated or for any other reason should put the the air pressure will be taken oil from the eliminating valve piston and the spring B will force this valve to normal position allowing air pressure to pass to the automatic air release valve A. and the engineers disabling valve B with the result that the train will be stopped automatically and the engineer will be unable Vto prevent such action. This taking ott of the air pressure from the eliminating valve may occur by Vthe discharge ot air past the ball h4 when this rises.

lt will be seen the et re that it' the engineer does not put the automatic brake valve in service position on approaching caution' lf he places it in service position the auto-v matic stop mechanism will be cut out of action and. thetrain lwill slow down. Ifhe places this valve H6 in service position to slow down, andy thereafter for any reason changes its positionwhile arm 18 of trigger valve is held by locking bolt 26, the automatic stop action will take place. p

It will be understood that as the equaliz'ing reservoir `is connected with the standard engineers valve shown at H6 (cal-led in the l/Vestinghouse literature automatic y,brake valve) the stopping of the train will be effected, not only when all the parts Vot the apparatus are in proper working condition, but also when a rupture'in any ofthe connections or when any parts are removed. y A rupture of the connections in any part of the improved system will cause a reduction of the pressure in the equalizing reservoir and as a. result the pressure in chamber D (so lettered in Westinghouse literature) ofthe automaticv brake valve'I-IG, above its piston will be reduced allowing this piston to rise and this will openV the brake pipe exhaust port to atmosphere andrelease train pipe pressure, and set the brakes. This exhaust port is indicated on the drawing at B. P. EX.

This action willtake place noinatter where the accidental rupture occurs in the improved apparatusor attachment, for instance at any oi the points markede, whether this be between the equalizing reservoir and the contact valve; or between the contact valve and the actuating (trigger) valve or between the actuating valve and the eliminating valve, or between the eliminating valve and the automatic service (air release) valve, or-between the automatic service valve and the disabling valve. v l c y Following out these various contingencies we will suppose` that a break occurs between the equalizing reservoir and the contact valve.

` This will immediately reduce pressure, in the equalizing reservoir with the result that the automatic brake valve (H6) will operate because of reduction of pressure in its chamber D and by consequent rise of its piston open its exhaust port to atmosphere for escape: of train pipe pressure.

lli' the rupture occurs between the contact valve 9, and the actuating valve (trigger valve) 19 pressure in the equalizing reservoir will be reduced, not immediately, butl when the Contact valve is-operated andtrfain pipe pressure will'be reduced through the eX- haust of automatic brake valve as before.

lf the rupture occurs between the actuatingV is operated by the setting ofthe Contact valve; in fact if the breakage occursA at any .point beyond the actuating valve i. e. between it and the eliminating valve; between the eliminating valve and the automatic service (autof matic air release)y valve, or between the automaticr service valve and the disabling valve the pressure in the equalizing reservoirwill be reduced,.not immediately, but thisrwill take place as soon as the actuating (trigger) valve.

isoperated by the contact valve. v 1t a break occurs between the disablin valve and the engineers independent brake valve this will infno way affect the automatic stopping operation, but will only prevent the engineer trom recharging the system yunt-il the break is repaired. n

In order that my improved control system may operate efficiently with a plurality 'of locomotives, as vtor instance on va vtrain provided with adouble header, l extend the pip-e y15 rearwardly for any suitable distance, as

for example tothe rear end of the tender, as indicated at 15?, where it terminates in the usual valved' ilexiblecoupling 152. v

At the iiront oi' the locomotive I locate a pipe .155" having a terminal valved flexible coupling adapted to be coupled to the rear end of the pipe extension 15X, which vpipe 15 communicates with the cylinder 35 in rearv of the pistonB. w l

Supposing pipe 15Y' of a following locomotive to be coupled to pipe lxfof the preceding locomotive, the operation of lever arm 18 of the Yiront locomotive and consequent admission of air toy pipe 15 will operate the brakes lnormal position, owing to the dog being held out of lengaging orlockingposition.-

Referring toFigure l which shows a lever 18 18 belonging to the trigger valve if either arm of thislever breaks a release of chamber D air will take place and the brakes will be set. To accomplish this the trigger arm or leveris provided with a passage 18C which receives air through the port or passagef18f, from the by-pass passage 19C, these twopasL sages being in communication through the space above the valve 19.v The trigger valve lever is provided with an opening 25 to engage the dog 26 andas shown inFigure a small air passage 18d extends aro/und this opening 25 in the wall of thelever or valve arm, this passage communicating withthe air passage 189 so that if breakage occurs at the part of the lever adjacent the opening 25 chamber D air will be released. If breakage occurs at either oney of the pistons 17, 17', the coupling; 17 f will be released and an valve 18e will be freed from the holding etfectof this coupling and the air from Vchamber D will then be free to escape by this valve.

izo

Another Jiorm is shown in Figurev 12 in which the arm ot the trigger valve is provided with an air port like that above described, but instead of using the coupling 17a Jetween the pistons 17 and 17, as in Fig. 3, these pistons in Figure 12 are shown hollow to receive the air pressure within them.

One or" these hollow pistons is marked 17X. If either one ot these pistons breaks the air `1will be released and the brakes set. rlhis improvement ot Fig. 12 avoids the use of the coupling 17 a of Figure3 and ot the valve 18e oi' said Figure 3.

It is obvious that if the trigger arm 18, 13

ot' Fig. 3 is entirely removed this will allow the escape o1 air trom chamber D.

Briefly stated I construct the lever of the trigger valve in such manner that it any porcob tion ot the same breaks release ot chamber D automatic brake valve whereby the engineer will be prevented from recharging the train pipe but can make a further train pipe reduction when the automatic air release valve is operated, a valve for supplying air to the automatic air release valve and the enginneers disabling valve for operating them, an eliminating` valve between said air supply valve and the automatic air release valve and engineers disabling valve, an air pipe connection from the engineers automatic brake valve to 'the eliminating valve for operating the same when the engineer sets his automatic brake valve in service position, and an -air supply connection between the engineers straight air valve and the disabling` valve for restoring` said valve to open position, substantially as described.

2. In combination in an air brake apparatus, a main air reservoir, a train' pipe, an automatic air release valve therefor, an engineers disabling valve in the pipe leading from the main air reservoir to the engineers vautomat-ic brake valve whereby the engineer lwill be prevented from recharging the train pipe but can make a further train pipe reduction when the automatic air release valve is operated, a valvefor supplying air to the automatic air release valve and the engineers disabling valve for operating theman eliminating valve between said air supply valve vand the automatic air release valve and engineers disabling valve, an air pipe connec- Lacasse tion from the engineers automatic'brake Vvalve to the eliminating valve foroperating the supply of air thereto until pressure builds up beyond said supply valve to a prescribed degree, and means tor then restoring said supply valve to closed position, and whereby, if thev engineer sets his automatic brake valve out of service position while the air supply valve is open, the consequent opening of the eliminating valve will supply air pressure to the automatic air release valve and to the disabling valve for their automatic operation,

substantially as described. A

3. In combination in an air brake apparatus, a main air reservoir, a train pipe, an automatic air release valve therefor, an engi- -neers disabling valve in the pipe leading from the main air reservoir to the engineers automatic brake valve whereby the engineer will be prevented from recharging the train pipe but can'make a. further train pipe reduction when the automatic air release valve is operated, a valve for supplying air to the automatic air release valve and the engineers disabling valve for operating them, an eliminating valve between said air supply valve and the automatic air release valve and engineers disabling valve, an air pipe connection from the engineers automatic brake valve to the eliminating valve 'for operating the same when the engineer sets his automatic brake valve in service position, and an air supply connection between the engineers straight air valve and the disabling valve for restoring said'valve to open position, .said air supply valve, when operated, remaining open to prolong the supply ot air to the automatic air release `valve and disabling valve, or when the eliminating valve is closed, prolonging the supply oit' air thereto until pressure builds up beyond said supplyvalve to a prescribed degree, and means 'lor then restoring said supply valve to closed position, and whereby, it the engineer sets his automat-ic brake valve out of service position while the air supply valve is open, the consequent opening of the eliminating valve will supply air pressure to the automatic air release valve and to the disabling valve for their automatic operation, a suitable lock being provided for holding the supply valveopen until the prescribed pressure is built up, whereupon said lock will be released, substantially as described.

' In testimony whereof, I affix my signature.

' PATRICK- J. CLIFFORD.

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